辺境モブ貴族のウチに嫁いできた悪役令嬢が、めちゃくちゃできる良い嫁なんだが？ (Associated Names)

Ragna has reincarnated as the third son of a noble family with lands in the frontier. Thrilled at the prospect of living freely in another world without the responsibility of inheriting the family estate, his excitement was short-lived. Following the death of his father and two brothers in battle, Ragna finds himself unexpectedly taking over…